When it comes to being an action star, many have tried and few have succeeded. Not everyone — even those with terrific acting skills — can make the leap to action hero.

A piercing gaze helps, and being a physical specimen never hurts (see Daniel Craig as James Bond), but the key is what's behind the eyes: relatability, emotional vulnerability, a glint of humor, an inner life.

Some stars are surprisingly adept at transporting themselves to an action mode — for example, Zoe Saldana as an avenging angel assassin in "Columbiana" — while others seem hopelessly ill-suited in these roles, like Shia LaBeouf in the most recent "Indiana Jones" movie.

As "Mad Max: Fury Road" transports viewers to an exhilarating alternate universe of hair-raising heroics, it's worth pondering why some actors seem born to the part while others flounder. Certainly, it's not mere muscles and macho that sway us.

The re-upped version of the 1979 apocalyptic classic stars Tom Hardy and Charlize Theron, a pair of stellar actors not known principally for their brawn. However, it's hard to imagine anyone doing it better than Hardy or Theron as the hard-bitten, death-defying and unstoppable heroes of the road-rage saga.

"Mad Max: Fury Road" will leave you speechless, which couldn't be more appropriate. Words are not really the point when it comes to dealing with this barn-burner of a post-apocalyptic extravaganza in which sizzling, unsettling images are the order of the day.

"Mad Max: Fury Road" will leave you speechless, which couldn't be more appropriate. Words are not really the point when it comes to dealing with this barn-burner of a post-apocalyptic extravaganza in which sizzling, unsettling images are the order of the day.

Both are superb dramatic actors, but that's only part of the equation. Jeremy Renner was outstanding as a soldier tasked with dismantling bombs in "The Hurt Locker," but he floundered as an updated Jason Bourne in "The Bourne Legacy." Jake Gyllenhaal was brilliant as a ghoulish paparazzo in "Nightcrawler" but not the royal for the job in "Prince of Persia." Both parts were hampered by shallowness.

Actors who can convey emotional complexity through physicality have an edge. Viewers need to feel their personal struggle, sense something poetic and urgent — even desperate — about their being. At the same time, we must be convinced of their strength, courage and commitment. Action stars need a healthy dose of stoicism but not rigidity. They can be still but never vacant, pared but not vacuous.

Charlize Theron

Jasin Boland, AP

Charlize Theron as Imperator Furiosa in "Mad Max: Fury Road."

Charlize Theron as Imperator Furiosa in "Mad Max: Fury Road."

(Jasin Boland, AP)

Quintessential survivors, they must be shape-shifters, ever-resilient, adaptable and resourceful, ready to jump and pivot as calamity looms. An essential lightness helps — on their feet, and in their attitude. Humor must lie beneath the surface, ready to materialize in the form of a sardonic quip, or a quick dose of withering wit. (Think Eastwood's "Go ahead, make my day.")

When Hardy's Max tells Theron's Furiosa "Hope is a mistake," we believe him intrinsically because we see he is emotionally haunted, pensive and world-weary.

Theron's one-armed Imperator Furiosa is formidable because she's fearless and mighty but also thoughtful. We sense her mind working as she pilots a behemoth fighting machine. She may smear axle grease on her face, but it doesn't obscure her eyes, which speak volumes. And it doesn't hurt that she looks comfortable shouldering a gun.

As Furiosa, Theron pilots an unwieldy big rig tricked out for war. We can see from her hooded gaze that she's ever-wary and plotting how to say alive, along with her precious cargo — a half-dozen baby breeders controlled by evil dictator Immortan Joe. She careens her way through billowing smoke and fiery explosions. When a war boy jumps onto her rig, she grabs him by the neck and spits in his face.

She's a sure shot, steadying her rifle on Max's shoulder for ballast, telling him "Don't breathe" as she fires a single bullet that takes out several gun-wielding enemies. She knifes an intruder who lunges after her with a chain saw and head-butts a hulking bad guy before annihilating her most hated enemy.

But she's more than a tough-as-nails warrior. Determined to reach her verdant birthplace, she's overcome when she realizes it's now a dried up wasteland. Ever-resilient, however, she decides to face peril in order to make things better. She retraces her treacherous journey to try to help the tyrannized masses.

A great action star knows how to fight, when to wield a weapon and how to convincingly evade capture in a chase to the death. Athleticism is key, whether it's the dancer's elegance of silent-film star Douglas Fairbanks or the thickly muscled version of Arnold Schwarzenegger.

Yet he or she is not impervious to pain nor successful in every clash. We're not talking about superheroes here but flesh-and-blood men and women. Or at least we have to believe they could be real in the world they inhabit.

The best have expressive faces, features that convey information and emotion with exquisite subtlety. Harrison Ford's tortured doctor seeking justice and redemption in "The Fugitive" displays an inner fury not with words but by clenching his jaw and narrowing his eyes.

They project indomitability, unflagging determination and a fierceness that's equal parts mental toughness and physical agility. It's their humanity we respond to instinctively. They are who we would like to think we'd be if faced with unimaginable peril.

The hyper-muscular Diesel looks as if he could pull off any manner of stunts, but it's Damon's less imposing physical specimen we believe most, whether he faces off against a stranger in a lightning-fast mano-a-mano battle or jumps across buildings in an exotic locale. We can see he's fast-thinking and never intransigent, willing to change course if necessary but not foolishly impulsive.

Impressive stature is certainly no detriment. However, it is not merely Dwayne Johnson's strapping physicality that assures us of his capabilities in the "Fast and Furious" franchise and the new disaster flick "San Andreas." His bulging muscles play off a self-deprecating wit, affability and evident intelligence.

It's the same for men or women. Sigourney Weaver is credible as Ripley in the "Alien" movies because she projects an intrepid nature, resolve and just enough vulnerability to draw us in. Theron has the same qualities in "Mad Max," intensified by integrity. Both Ripley and Furiosa make bold decisions, undaunted by fear, ready to accept the consequences.

Craig offers a new take on the 50-year-old James Bond series. Gruffer and more volatile than suave, he brings his own stamp to the British spy. He has a low-key charm, but his coiled ferocity is just below the surface. More taciturn than previous Bonds, he dispenses with the dapper niceties and idle womanizing that defined the other Bonds.

He's not impervious to pain, physical or emotional, and exudes a blend of recklessness and flexibility that's thoroughly convincing. He also conveys that he's wounded by life — something not seen much in the Bond universe. There's only so much a martini can assuage.

It's easy to spot the ones that do it right: Craig as James Bond, Scarlett Johansson as a drug-enhanced genius in "Lucy," Liam Neeson as a father hell-bent on saving his daughter in "Taken," Ford as Indiana Jones, Tom Cruise in "Mission Impossible: Ghost Protocol," Michelle Yeoh as a 19th century warrior in "Crouching Tiger, Hidden Dragon."

Even if some of their action sequences feel outlandish or in the realm of fantasy, these actors sell it, inspiring us to plunge headlong on a wild ride and follow them wherever they go.

Puig is a film critic for KPCC's Film Week. She was the film critic for USA Today and has written for the L.A. Times and DGA Quarterly and provided commentary and analysis for NPR, NBC, CBS, CNN and KCET. She is a member of the Los Angeles Film Critics Assn. and Women Film Critics Circle.